Are you worried about losing a great deal of your country to the sea? Most people are, in a vague, “Yeah I suppose” kind of way. Sadly, this is not a vague threat. This is an absolute, it will happen and people will lose homes and land.
This is not a glamourous topic. It won’t ever feature on Question Time and it won’t make the news until it is too late.
So why did I bring this up? Well mainly it’s because it is something that I did my undergraduate dissertation on. Specifically I looked at the most viable solution to coastal erosion and flooding. The best solution is to plant saltmarshes. I’ll save you the frankly tedious nature of my dissertation and skip to the punchline.
Protective seawalls do not work. Yes they stop the wave but they simply deflect the energy and over time they are worn down. As they wear down pieces of stone break off and erode the wall further leading to a vicious cycle. Oh, and it costs £5,000,000 per kilometre for a wall which has a lifespan of 10 years.
A more viable solution is “soft defences” which basically means planting saltmarshes, reed like plants. Saltmarshes are unique in that they exist around the tide mark and are flexible so they attenuate the wave energy by up to 99%. They also trap sediment forms a natural slope to the beach which further slows the wave. They are entirely natural in the UK and used to almost entirely surround us. Sadly, seawalls became fashionable and we go rid of the saltmarshes for something much more inefficient.
The last 50 years have resulted in an 80% decline in saltmarshes.
It’s remarkable that we are so woefully underprepared, especially in light of the fact that the United States and the Netherlands have been actively encouraging the world to replant saltmarshes as the most effective way of attenuating sea level rise and coastal erosion. It’s no coincidence that both of these nations are leading the way due to much of their respective population living in low laying coastal areas
Quite frankly though no one profits saltmarshes, no one gets rich. However, we save our coastline, provide a habitat for birds, fish and invertebrates which is surely a worthwhile goal? Saltmarsh restoration is an easy, cheap and viable solution and until it becomes popular we are at risk.
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